The present disclosure relates to semiconductor integrated circuits, and more specifically to a silicon-on-insulator chip comprising <100> oriented transistors.
Application of longitudinal stress—stress applied in the direction of current flow—modifies the mobilities of electrons and holes in NMOS and PMOS transistors, respectively. By using a conventional bulk silicon substrate with a (001) surface orientation and forming transistors with source-to-drain orientation in <110> directions, application of longitudinal stress leads to different reactions for electrons and holes. When a stress is applied in the longitudinal direction, either the electron mobility is increased and the hole mobility is decreased, or the electron mobility is decreased and the hole mobility is increased.